Amino Acid Metabolism in Gilthead Seabream Is Affected by the Dietary Protein to Energy Ratios

Table 1

Formulation and proximate composition of experimental diets.

Ingredients (%)	LowP/E	HighP/E
Fishmeal SP^a	22.00	22.00
Fishmeal^b	5.00	5.00
Soy protein concentrate^c	6.40	6.00
Wheat gluten^d	7.00	6.00
Corn gluten^e	11.00	11.00
Soybean meal^f	12.00	12.00
Rapeseed meal^g	5.00	5.00
Sunflower meal^h	4.00	5.00
Wheat meal^i	2.90	8.90
Whole peas^j	3.00	4.00
Fish oil^k	10.60	6.50
Rapeseed oil^l	6.60	4.10
Vitamin and mineral premix^m	1.00	1.00
Vitamin E^n	0.10	0.10
Choline chloride^o	0.10	0.10
Betaine HCl^p	0.50	0.50
Soy lecithin^q	0.50	0.50
Guar gum^r	0.50	0.50
Antioxidant powder^s	0.20	0.20
Mono-calcium phosphate^t	1.10	1.10
L-lysine^u	0.30	0.30
L-threonine^v	0.20	0.20
Proximate composition (% as fed)
Dry matter	94.2	93.2
Ash	8.5	8.8
Crude protein	44.7	44.8
Crude lipids	20.3	13.8
Total phosphorus	1.2	1.2
Gross energy (kJ g^-1)	22.3	21.0
P/E ratio (mg kJ^-1)	20.0	21.4

All values are reported as mean of duplicate analysis. P/E, protein to energy ratio. ^aSuper-Prime: 68% crude protein (CP), 8% crude fat (CF); Pesquera Diamante, Peru. ^bCONRESA 60: 65% CP, 10% CF; Conserveros Reunidos S.A., Spain. ^cSoycomil P: 63% CP, 8% CF; ADM, The Netherlands. ^dVITAL: 80% CP, 7.5% CF; Roquette Frères, France. ^eCorn gluten meal: 61% CP, 6% CF; COPAM, Portugal. ^fSolvent extracted dehulled soybean meal: 47% CP, 2.6% CF; CARGILL, Spain. ^gDefatted rapeseed meal: 34% CP, 2% CF; Premix Lda., Portugal. ^hSolvent extracted dehulled sunflower meal: 43% CP, 3% CF; MAZZOLENI SPA, Italy. ⁱWheat meal: 10% CP, 1.2% CF; Casa Lanchinha, Portugal.^j Yellow peas: 19.6% CP, 2.2% CF; Ribeiro e Sousa Lda., Portugal.^k Sopropêche, France.^l J.C. Coimbra Lda., Portugal. ^mPREMIX Lda., Portugal: Vitamins (IU or mg kg^-1 diet): DL-alpha tocoferol acetate 100 mg; sodium menadione bisulphate 25 mg; retinyl acetate 20 000 IU; DL-cholecalciferol 2 000 IU; thiamin 30 mg; riboflavin 30 mg; pyridoxine 20 mg; cyanocobalamine 0.1 mg; nicotinic acid 200 mg; folic acid 15 mg; ascorbic acid 1 000 mg; inositol 500 mg; biotin 3 mg; calcium panthotenate 100 mg; choline chloride 1 000 mg; and betaine 500 mg. Minerals (g or mg kg^-1 diet): cobalt carbonate 0.65 mg; copper sulphate 9 mg; ferric sulphate 6 mg; potassium iodide 0.5 mg; manganese oxide 9.6 mg; sodium selenite 0.01 mg; zinc sulphate 7.5 mg; sodium chloride 400 mg; calcium carbonate 1.86 g; and excipient wheat middlings. ⁿROVIMIX E50, DSM Nutritional Products, Switzerland.^o ORFFA, The Netherlands. ^pBeta-Key 95%, ORFFA, The Netherlands. ^qLecico P700IPM, LECICO GmbH, Germany. ^rGuar gum, Seah International, France. ^sParamega PX, KEMIN EUROPE NV, Belgium. ^tMCP: 22% P, 18% Ca; Fosfitalia, Italy. ^uL-Lysine HCl 99%; Ajinomoto Eurolysine SAS, France. ^vL-Threonine: 98%; EVONIK Nutrition & Care GmbH, Germany.